Magnetic susceptibility and spin-glass behavior in the pseudo-one-dimensional mixed system [(CH3)3NH]Co1−xNixCl3⋅2H2O and the analogous Co-Mn and Ni-Mn systems

The magnetic behavior of the pseudo-one-dimensional mixed systems [(${\mathrm{CH}}_3$ ${)}_3$NH]${\mathit{A}}_{\left(1\mathrm{}\mathrm{-}\mathit{x}\right)}$ ${\mathit{B}}_{\mathit{x}}$ ${\mathrm{Cl}}_3$⋅${2\mathrm{H}}_2$O, where A and B are Co, Ni, and Mn, have been investigated as a function of x. The mixture with Co and Ni has been found to exhibit spin-glass behavior below a characteristic temperature $T_g$ as evidenced by the onset of time-dependent thermoremanent magnetization. The phase diagram of temperature versus x shows a very broad and deep spin-glass region with unusually thin antiferromagnetic phase regions above it. Evidence for a tetracritical point near x=0.58 is indicated. Thermoremanent magnetization versus time below $T_g$ has been fit to a stretched exponential function plus a constant offset. Since the mixtures with Mn with Co and Mn with Ni show no spin-glass behavior, these systems show that the critical dimensionality for spin-glass behavior must be greater than one.